Provide no funds up front; negotiate this and use a reputable international law firm to construct all contracts;
If possible, have the contract negotiated in the USA, and select jurisdiction of USA state court of your residence.
Pay funds to a USA escrow account as required in the contract.
Get all the information of the seller, personal data, do a search for any issues/reputation etc...
Assume the property will be delivered very late; also, assume the finishes will be faulty and require retouching before paying.
Ensure the electric/ plumbing/sewage are all at USA standards and inspect the systems well before paying.
Check to ensure that property taxes are paid up on the project / property you are purchasing.
Assume all is not what it seems.